Article

CT Colonography: Performance and Program Outcome Measures in an Older Screening Population 1

Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Science Center, 600 Highland Ave, Madison, WI 53792-3252, USA.
Radiology (Impact Factor: 6.87). 02/2010; 254(2):493-500. DOI: 10.1148/radiol.09091478
Source: PubMed

ABSTRACT

To evaluate computed tomographic (CT) colonography performance and program outcome measures in an older cohort (65-79 years) of an established large-scale colorectal cancer screening program.
This HIPAA-compliant study was approved by the institutional review board; informed consent waived. Retrospective analysis of the 65-79-year-old cohort (n = 577) from the University of Wisconsin CT colonography screening program (n = 5176) was undertaken. Performance and outcome measures including advanced neoplasia prevalence and colonoscopy referral, extracolonic finding, extracolonic work-up, and complication rates were obtained by using a CT colonography database and review of medical records. Comparisons between the older cohort and the general screening population were made by using the Student t, Pearson chi(2), and Fisher exact tests. A P value <or= .05 was considered to indicate a significant difference.
With a 6-mm threshold for positivity, the overall referral rate to optical colonoscopy was 15.3% (88 of 577), leading to 277 polypectomies and the removal of 103 nondiminutive adenomas. For adenomas, the per-patient positivity rates were 10.9% (63 of 577) and 6.8% (39 of 577) at the 6- and 10-mm thresholds, respectively. The prevalence of advanced neoplasia was 7.6% (44 of 577). Fifty-four adenomas met advanced status, and five unsuspected cancers were detected. The advanced neoplasias identified were typically large, with a mean size of 21 mm. Potentially important extracolonic findings were seen in 15.4% (89 of 577) of patients, with a work-up rate of 7.8% (45 of 577). The majority of important extracolonic diagnoses were vascular aneurysms (n = 18). No major complications were encountered.
CT colonography is a safe and effective screening modality for the older population.

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    • "Our analyses suggest that patients who undergo initial CTC, with or without subsequent OC, may experience lower rates of serious gastrointestinal, other gastrointestinal and cardiovascular events compared to patients who receive initial OC. This finding is intuitively reasonable, given that CTC does not require sedation and the intention of CTC is to selectively refer the approximately 8–15% of patients with suspected clinically significant polyps (N6 mm) and masses to OC for further evaluation (Kim et al., 2007, 2010; Macari et al., 2011). However, it is important to recognize that we were unable to fully adjust for differences between the groups based upon the information available in claims data. "
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    • "CTC performance has been evaluated in senior patient cohorts (age 65 years). A retrospective analysis of 577 subjects found an excellent CTCecolonoscopy concordance rate of 91%[68]. Based on a 6-mm threshold, there was an overall patient referral rate of 15% for colonoscopy. "
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